Dental caries continues to be prevalent in children and youth, with significant oral health disparities existing in some population groups. This disease arises when the balance between pathological factors (e.g. cariogenic bacteria) and protective factors (e.g. saliva flow) is tipped in favour of demineralization. The prevalence of caries suggests that the disease is not being effectively managed with an emphasis traditionally on restorative procedures where caries lesions are already serious. Dentistry is undergoing a paradigm shift away from surgical treatment of caries to a medical model of disease prevention and management. This change aims to address the disease cause with minimally invasive CAries Management By Risk Assessment (CAMBRA) efforts. For this paradigm to be successful, dentists need better tools to detect early lesions. Early detection will allow dentists to monitor and counsel patients in managing caries risk factors to help prevent disease progression. We hypothesize that the combination of morphological and biochemical information provided by optical coherence tomography (OCT) and polarized Raman spectroscopy (PRS), respectively, can provide clinicians with an improved tool to detect and assess early caries lesions as well as to be used for both short- and long-term monitoring for better caries management. The overall objective of this competitive renewal proposal is to develop a novel software and hardware clinical platform based on a combined OCT-PRS intra-oral probe for early dental caries detection and assessment. To achieve this goal we plan to: 1) establish a clinic-friendly software platform to derive caries relevant parameters from the OCT-PRS data, 2) develop combined OCT-PRS caries assessment intra-oral probes for proximal and occlusal surfaces, and finally 3) validate the hardware and software for clinical utility in caries detectio and assessment through two small scale clinical studies. Our research will provide novel automated software algorithms to provide clinicians with measures of caries presence, lesion extent, quantitative assessment of caries lesion activity and mineralization status during the examination of the patient. The proposed developments and evidence-based findings will support a paradigm shift in treating caries as a disease. This research supports the new US Healthy People 2020 program in which an oral health objective is to reduce caries and untreated decay among children and adolescents.